Re: module oops tracking [Re: [PATCH] cheap lookup of symbol names on oops()]

Andrea Arcangeli
2002-07-28T22:50:14Z

On Sat, Jul 27, 2002 at 11:33:11AM +1000, Keith Owens wrote:
> On Sat, 27 Jul 2002 03:19:06 +0200,
> Andrea Arcangeli <andrea@suse.de> wrote:
> >here an updated patch that moves the bitflag from the dedicated array to
> >the mod->flags per your suggesiton.
> >Oops: 0002
> >2.4.19-rc3aa2 #3 SMP Sat Jul 27 05:06:19 CEST 2002
>
> Kernel version without any identifying string cannot be picked up by
> ksymoops. Can you append the kernel version to the die message? That
> means changing all arch/*/traps.c but it saves a line on the console.
>
> Oops: 0002 2.4.19-rc3aa2 #3 SMP Sat Jul 27 05:06:19 CEST 2002

ok, it saves one more line (will be in next -aa too, for rc3aa2 it's too
late 8).

diff -urNp z/arch/i386/kernel/traps.c 2.4.19rc3aa2/arch/i386/kernel/traps.c
--- z/arch/i386/kernel/traps.c Sat Jul 27 03:42:39 2002
+++ 2.4.19rc3aa2/arch/i386/kernel/traps.c Sat Jul 27 03:41:56 2002
@@ -113,6 +113,7 @@ static inline int kernel_text_address(un
* module area. Of course it'd be better to test only
* for the .text subset... */
if (mod_bound(addr, 0, mod)) {
+ module_oops_tracking_mark(mod);
retval = 1;
break;
}
@@ -208,6 +209,8 @@ void show_registers(struct pt_regs *regs
esp = regs->esp;
ss = regs->xss & 0xffff;
}
+ module_oops_tracking_init();
+ kernel_text_address(regs->eip);
printk("CPU: %d\nEIP: %04x:[<%08lx>] %s\nEFLAGS: %08lx\n",
smp_processor_id(), 0xffff & regs->xcs, regs->eip, print_tainted(), regs->eflags);
printk("eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
@@ -226,8 +229,9 @@ void show_registers(struct pt_regs *regs

printk("\nStack: ");
show_stack((unsigned long*)esp);
+ module_oops_tracking_print();

- printk("\nCode: ");
+ printk("Code: ");
if(regs->eip < PAGE_OFFSET)
goto bad;

@@ -288,7 +292,8 @@ void die(const char * str, struct pt_reg
spin_lock_irq(&die_lock);
bust_spinlocks(1);
handle_BUG(regs);
- printk("%s: %04lx\n", str, err & 0xffff);
+ printk("%s: %04lx ", str, err & 0xffff);
+ printk(oops_id);
show_registers(regs);
bust_spinlocks(0);
spin_unlock_irq(&die_lock);
diff -urNp z/include/linux/kernel.h 2.4.19rc3aa2/include/linux/kernel.h
--- z/include/linux/kernel.h Sat Jul 27 03:42:39 2002
+++ 2.4.19rc3aa2/include/linux/kernel.h Sat Jul 27 04:57:04 2002
@@ -109,6 +109,8 @@ extern const char *print_tainted(void);

extern void dump_stack(void);

+extern char *oops_id;
+
#if DEBUG
#define pr_debug(fmt,arg...) \
printk(KERN_DEBUG fmt,##arg)
diff -urNp z/include/linux/module.h 2.4.19rc3aa2/include/linux/module.h
--- z/include/linux/module.h Sat Jul 27 03:42:39 2002
+++ 2.4.19rc3aa2/include/linux/module.h Sat Jul 27 04:57:40 2002
@@ -110,6 +110,7 @@ struct module_info
#define MOD_USED_ONCE 16
#define MOD_JUST_FREED 32
#define MOD_INITIALIZING 64
+#define MOD_OOPS_PRINT 128

/* Values for query_module's which. */

@@ -411,4 +412,14 @@ __attribute__((section("__ksymtab"))) =
#define SET_MODULE_OWNER(some_struct) do { } while (0)
#endif

+#ifdef CONFIG_MODULES
+extern void module_oops_tracking_init(void);
+extern void module_oops_tracking_mark(struct module *);
+extern void module_oops_tracking_print(void);
+#else
+#define module_oops_tracking_init() do { } while (0)
+#define module_oops_tracking_mark(x) do { } while (0)
+#define module_oops_tracking_print() do { } while (0)
+#endif
+
#endif /* _LINUX_MODULE_H */
diff -urNp z/init/version.c 2.4.19rc3aa2/init/version.c
--- z/init/version.c Sat Jul 27 03:42:39 2002
+++ 2.4.19rc3aa2/init/version.c Sat Jul 27 05:03:14 2002
@@ -24,3 +24,5 @@ struct new_utsname system_utsname = {
const char *linux_banner =
"Linux version " UTS_RELEASE " (" LINUX_COMPILE_BY "@"
LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION "\n";
+
+const char *oops_id = UTS_RELEASE " " UTS_VERSION "\n";
diff -urNp z/kernel/module.c 2.4.19rc3aa2/kernel/module.c
--- z/kernel/module.c Sat Jul 27 03:42:39 2002
+++ 2.4.19rc3aa2/kernel/module.c Sat Jul 27 02:38:24 2002
@@ -1242,6 +1242,50 @@ struct seq_operations ksyms_op = {
show: s_show
};

+/*
+ * The module tracking logic assumes the module list doesn't
+ * change under the oops. In case of a race we could get not
+ * the exact information about the affected modules, but it's
+ * almost impossible to trigger and it's a not interesting case.
+ * This code runs protected by the die_lock spinlock, the arch/
+ * caller takes care of it.
+ */
+void module_oops_tracking_init(void)
+{
+ struct module * mod;
+
+ for (mod = module_list; mod != &kernel_module; mod = mod->next)
+ mod->flags &= MOD_OOPS_PRINT;
+}
+
+void module_oops_tracking_mark(struct module * mod)
+{
+ mod->flags |= MOD_OOPS_PRINT;
+}
+
+void module_oops_tracking_print(void)
+{
+ struct module *mod;
+ int i = 0;
+
+ for (mod = module_list; mod != &kernel_module; mod = mod->next) {
+ if (!(mod->flags & MOD_OOPS_PRINT))
+ continue;
+ if (!i)
+ printk("Modules:");
+ if (i && !(i % 2))
+ printk("\n ");
+ i++;
+
+ printk(" [(%s:<%p>:<%p>)]",
+ mod->name,
+ (char *) mod + mod->size_of_struct,
+ (char *) mod + mod->size);
+ }
+ if (i)
+ printk("\n");
+}
+
#else /* CONFIG_MODULES */

/* Dummy syscalls for people who don't want modules */

Andrea